I am using ATG 10.1, migrated from 10.0.3 version.
When I try to finish an order, I am getting this error:

The payment group pg880004 could not be authorized for payment: The request to authorize the amount 1285.92 failed because it would result in an overauthorization for PaymentGroup pg880004..

My error.log file contains this exception:

**** Error 1360760614148 /atg/commerce/order/purchase/RepriceOrderDroplet
--- CONTAINER:atg.service.pipeline.RunProcessException: An exception was thrown from the context of the link named [executeRepriceOrderChainForUpdate].; SOURCE:CONTAINER:atg.service.pipeline.RunProcessException: An exception was thrown from the context of the link named [priceOrderTotal].; SOURCE:java.lang.NullPointerException

I read this post Payment Group Error in ATG and I couldn't find the answer.
Because of this error, I can't do any order in my store and in Service Center.